Vacuum-fuel system for carburetors



April 5, 1927.- `1,623,237 N. EcKLEs VACUUM FUEL SYSTEM -FOR CARBURETORS f Filed Jan.20. 1921 2Shees-$heet 1 1,623,27 Apnl 5,1927. NECKLES 3 VACUUM FUEL SS'IEMNFOR CARBURETORS Filed Jan. 20, 1921 2 Sheets-Sheet 2 Patented Apr. i, 1927.

UNITED STATES PATENT OFFICE.

NOBLE ECKLES, 0F SAN DIEGO, CALIFORNIA, .ASSIGNOR OF THREE-FOURTHS TO LEWIS W. RHODE, OF SAN DIEGO, CALIFORNIA.

VACUUM-FUEL SYSTEM FOR CARURETORS.

Application filed January 20, 1921. Serial No. 438,689.

vThis invention relates to carburctors, and particularly to that type of carburetor wherein fuel flows from a fuel supply tank into the carburetor as needed, the fuel being drawn into the supply tank from a main supply tank to keep the first named supply tank constantly filled.

One object of the invention is to provide a carburetor so designed as to draw its own fuel from the supply tank without Vthe use either of a vacuum tank system or a system wherein air pressure in the main supply ank forces the fuel into the float chambers of the carburetor, which is particularly dangerous if there should be a leak in the fuel line.

A further object is to provide a carburetor which will secure a proper supply of fuel from a tank located either above or below the carburetor.

A. further object is to provide a carburetorof this character of such simple con struction that it can be manufactured at minimum cost and in which there are no springs or other delicate mechanism to get out of order or adjustment.

And a further object is to provide a carburetor of this character including a secondary supply tank connected to the inspirator nozele of the carburetor, this supply tank being in turn connected to a primary supply tank, the upper end of the secondary supply tank being connected by an airV duct to the interior of the carburetor in advance of the throttle 'valve so that the pressure within the upper end of the tank and within the body of the carburetor will be equalized and fuel may be drawn into the secondary tank from the primary tank when the float in the secondary tank lowers a predetermined amount due to the use of fuel, this float on rising closing the inlet from the primary tank.

And still another object is to provide a carburetor of this character with the tank of the character described divided into two chambers, the lower chamber being directlyr A further object is to provide a construction of the character described wherein the lioat chambers work continuously under a partial vacuum until the motor stops, when they return to atmospheric pressure.

@ther objects will appear in the course of the following` description.

Myinvention is illustrated in the accompanying drawings, wherein :--y

Figurel is a longitudinal sectional view of a carburetor with the supply tank connected thereto constructed in accordance with my invention;

Figure 2 is a vertical sectional view of the supply tank; y

Figure 3 is a fragmentary vertical section on the same plane as Figure 1 but showing a modification in the position o-f the vacuum relief valve; p

Referring to ythese drawings, designates the body of the carburetor, which is circular in cross section and somewhat elongated, one end of this circular body being formed with a flange 1l whereby the carburetor may be attached to the intake manifold ofthe engine. This carburetor is provided at its end adjacent the flange 11 with a throttle valve 12 mounted as usual upon the stem lvhaving tie usual crank arm whereby it may be connected to the usual.

carburetor operating mechanism. Just forward of the throttle valve L12 and terminating approximately at the pivotal axis of the throttle valve a Venturi-member 14 deiining'a Venturi passage 15. The wall of the body 10 at its end remote from the flange 11 is formed with an air intake opening 16 having a valve seat 17.

Disposed above this opening is a cylinder 18 closed at its upper end `and open at its lower end, this cylinder being supported by a spider or legs 19. Extending longitudinally through vone wall of the carburetor, as for instance the upper wall, as illustrated, is a duct 20 which opens at one end to the interior of the carburetor body behind the throttle valve 12, at 21. The other end of this duct is continued, as at 22, through one of the legs .19 and up through the wall of the cylinder' 18, opening for a distance along the upper end of this cylinder. Disposed within the cylinder 18 is an elongated piston 23 which has a length approximately equal to Vthat portion of the duct 22 which extends vertically in the lwall 18, this piston having a stem 24, and attached to this stem is a valve seating against the seat 17 when the valve is raised. This valve 25 constitutes an air valve and when this valve is lowered to its full extent, a maximum amount of air is permitted to enter through the opening I6 into the interior ofthe carburetor, and as this valve is raised, the amount of this air is reduced until, when the valve is fully raised, no air enters through this opening 16.

lhile I have illustrated a carburetor body of peculiar construction and having the suction controlled air inlet, this forms no part of my present invention. but this -present invention relates to the fuel feed mechanism. rihis n'ieans, however, for controlling the inlet of air to the carburetor forms the subject matter of an application of even date herewith.

Associated with the carburetor body is a secondary supply tank designated 26 which is divided into two chambers 27 and 28 by a transverse partition 29. From the lower end of the chamber 28 exten-ds a supply pipe 30, the flow through which is controlled by the needle valve 8l. This supply pipe 8O extends laterally from the compartment 28 and then extends upward into the carburetor body l() at the beginning of the Venturi passage 15 and then extends forward and terminates in a spray `nozzle 32. Extending upward through the bottom of the carburetor body and terminating at the supply nozzle is an air tube 33. The air sucked up through this air tube or pipe 83 acts to break up and atomize the particles of gasoline discharged from the spray nozzle 32.

The upper end of the chamber 27 is connected by a pipe 34 to a primary supply tank or other source of supply, and passage 'from this pipe 34 into the chamber 27 is controlled by means of a valve 85 which, when the level of the fuel within the chamber 27 is at its highest, is held closed by means of the usual annular float 36 mounted upon a hinged arm 37. `When thisl tloat rises to a predetermined position` it closes the valve 35, which thus constitutes a float controlled valve. and when the'float 36 lowers, owing to the discharge of fuel from the chamber 27, the valve lowers, thus permitting the iniiow of fuel through the pipe 84 into the chamber 27. The chamber 28 communicates with chamber 27 by means of a port 38 normally closed by a float controlled valve 39 of the same character as the valve 35, this valve beii'rg` held in its close-d position by a float 4() connected to a hinged arm 41.

liixtending` vertically upward through the tank 26 is a pipe 42 which at its lower end comnuinicates with the interior of the carburetor body lO in advance of the spray nozzle. This pipe 42 opens at its upper end, as at 43, into the upper end of the chamber 27 and has an opening 43a into the upper end of the chamber 28. Thus it will be seen that the pressure in the upper portion of the chamber 27, in the upper portion of thechamber 28, and in the carburetor body will be equalized.

The top ofthe chamber 27 is provided with a valve 44 whereby air may be admitted into the upper end of the chamber 27 and through pipe 42 into the upper end of the chamber 28 to break the vacuum therein and permit the liquid fuel within the chamber 28 to 'flow freely through the pipe 80 and out through the spray nozzle 32 to thus prime the engine. The upper end of the chamber 27 is also provided with a small vent opening 45 controlled by an adjustable valve 46. This constitutes an adjustable air vent, the purpose of which is to provide means whereby the vacuum existing in the float chambers may be very slightly reduced, thus breaking the capillary attraction existing at the spray nozzle discharge end at very low motor speeds. I hav-e disclosed this air vent as being in the top of the upper float chamber, but I do not wish to be limited to this, as this air vent and valve can be placed in any convenient position upon the carburetor and even in direct communication with the pipe 42 at any position of this pipe, and this air vent might be applied upon the bottom of the carburetor as a consequence and open din rectly into the lower end of the pipe 42 where this pipe opens into the body l0. I have illustrated this modilication in detail view in Figure 3.

lVhile I do not wish to be limited to the particular construction of the tank 26, I have illustrated this tank as being composed of a cylindrical wall and upper and lower heads detachably engaged with said wall by a longitudinally extending bolt 47 having nuts 48 at its ends. I do not wish to be limited to the exact details of construction illustrated and the exact arrangement of parts illustrate-d, as it is obvious that these may be changed in many ways without departing from the spirit of the invention, and it will be understood that the drawing to which this description refers is purely illust 'ative of one embodiment of my invention.

I do not wish to be limited to the details of this combination of the carburetor with the fuel feeding means, as the fuel feeding- A lli) the engine is running at low speed, then at this time the vacuum created in the intake manifold is at its maximum. It is at this time that it is necessary to reduce the amount of air entering the carburetor to a minimum in proportion to the fuel. In other words, when a motor is idling it should have a greater' proportion of fuel than it does air. Ina-smuch as the vacuum behind the nearly closed throttle valve 12 is at its highest, it follows that air will be exhausted through the duct 2O from the upper portion of the cylinder 18 and this will canse the piston o3 to rise, thus closing the air port 16 or very greatly reducing the amount of air passing through this port, and thus a partial vacuum will be created in the interior of the body 10 of the carburetor. This vacuum is transmitted by pipe 4t2 to the lower float chamber 28 and to the upper float chamber. This causes the fuel to be drawn from the' primary supply tank to the carburetor float chamber 27, through pipe 34.

Assuming that the level of the fuel in the lower float chamber 28 has been reduced and the valve 39 is open, it is obvious that the fuel will pass from the upper chamber 27 into the lower float chamber until the float 40 rises sufficiently to close the valve 88. The reserve chamber 27 will then till to its proper level until the valve 35 closes. Thus it will be seen that the vacuum created in the main casing or passage of the carburetor body 10, the lower float chamber and the upper float chamber has been equalized and remains so throughout the 'operation of the engine. This partial vacuum which is kept within these chambers by the suction through the carburetor body causes the float chambers to continually replenish themselves so long as any fuel exists in the main or primary supply tank. lVhen the throttle valve is opened wider, the degree of vacuum behind the throttle valve l2 is, of course, reduced., thus reducing the vacuum in the upper end of the chamber 18, whereupon the weight of the piston 23 causes it to descend, thus shifting the valve 25 away from its seat 17 and permitting air to enter the body of the carburetor in advance of the spray nozzle 32.

The object of forming the duct 22 so that it opens into the cylinder 18 for a relatively long distance and extends to the upper end of the cylinder 18 and for the use of the relatively long piston 23 is that the partial vacuum created on one side of the piston draws it against that side of the cylinder wherein the duct 22 is located, thus preventing any slight reciprocation of the air valve and piston. In other words, this suction creates friction between the cylinder and the piston when the engine is running at low speeds. This is an essential feature, as it eliminates any complicated means for stopping this reciprocating motion yof the piston and air valve. By using a long cylinder and a long piston, a much larger bearing surface is secured between the piston and the cylinder. y

The particular object of the air valve'25 with its controlling means when in combination with the upper and lower fuel chambers 27 and 28 is for the purpose of creating a partial vacuum in the mixing cha-mber of the carburetor, which in turn creates a vacuum of equal volume in both float chambers, thus supplying. both ioat chambers with fuel from an outside source. Furthermore, the air valve 25 and its allied parts causes a vacuum of less intensity in the float chambers than would be created if the float chambers were directly connected to the carburetor ahead of the throttle valve. The advantage gained in this is that it enables the use of smaller ioats and smaller ioat valves than would be necessary if the float chambers were connected 'to the carburetor ahead of the throttle valve where the suction is more intense.

I claim l A carburetor having a suction passage, a spray nozzle discharging into the suction passage and a fuel tank divided into two chambers, one of said chambers being connected to the spray nozzle at its lower end, the other of said chambers having a. fuel inill? let pipe, a float means controlling the inlet into the last named chamber, a float controlling the passage of fuel from the last named chamber' to the other chamber i continuous communication with the upper ends of both chambers and with the suction passage of the carburetor whereby to maintain a partial vacuum in the upper portion of both fuel chambers while there is a partial vacuum in the suction passage of the carburetor, means a'djustably regulatable for relieving without breaking a partial vacuum formed in' the fuel chambers and manually operable means for breaking the vacuum of the chamber.

In testimony whereof I hereunto aliix my signature.

NOBLE ECKLES.

and a pipe in Y 

